MSc thesis project proposal

[2022-23] IC for precision GaN magnetic sensors.

Gallium Nitride is an exciting semiconductor because of its wide bandgap – which makes it operate in harsh environments far beyond that of Silicon. It also has been recently shown to have high-performance sensitivity, stability over a large temperature range, and record-low residual offset. However, these specs were limited by the benchtop equipment used in the measurements. To prove GaN is even better, high performance processing is needed with low noise amplifiers and low-residual current spinning. These can be accomplished with modern CMOS integrated circuits.


Project Tasks

In this project, you will:

  • Design a processing circuit for current spinning and amplifying GaN Hall effect sensors, in collaboration with Prof. Dr. Kofi Makinwa.
  • Tapeout the circuit on a CMOS process
  • Collaborate with Stanford university on their upcoming GaN processing run (led by Dr. Seneksy)
  • Package and test chip with GaN device
  • Test temperature range of co-packaged system from extreme low to high temperatures



Recommended Background (but not all is required - you can learn in the project!)

  • CMOS circuit design
  • Experience with Cadence
  • Semiconductor physics
  • Benchtop device testing
  • Interest in magnetic sensing applications!


Recommended Reading

GaN Hall Sensors:

  1. Dowling, Karen M., et al. "Micro-tesla offset in thermally stable AlGaN/GaN 2DEG Hall plates using current spinning." IEEE Sensors Letters 3.3 (2019): 1-4.10.1109/LSENS.2019.2898157
  2. Alpert, H. S., et al. "Sensitivity of 2DEG-based Hall-effect sensors at high temperatures." Review of Scientific Instruments 91.2 (2020): 025003.
  3. Dowling, Karen M., et al. "Low offset and noise in high biased GaN 2DEG Hall-effect plates investigated with infrared microscopy." Journal of Microelectromechanical Systems 29.5 (2020): 669-676.10.1109/JMEMS.2020.3013187

Si CMOS processing of Hall Sensors:

  1. Jouyaeian, Amirhossein, et al. "5.6 A 25A Hybrid Magnetic Current Sensor with 64mA Resolution, 1.8 MHz Bandwidth, and a Gain Drift Compensation Scheme." 2021 IEEE International Solid-State Circuits Conference (ISSCC). Vol. 64. IEEE, 2021.10.1109/ISSCC42613.2021.9365767
  2. Van Der Meer, Jeroen C., et al. "A fully integrated CMOS Hall sensor with a 3.65/spl mu/T 3/spl sigma/offset for compass applications." ISSCC. 2005 IEEE International Digest of Technical Papers. Solid-State Circuits Conference, 2005.. IEEE, 2005. 10.1109/ISSCC.2005.1493961


dr. Karen Dowling

Electronic Instrumentation Group

Department of Microelectronics

Last modified: 2022-09-26